Resource allocation and channel access control in multimedia wireless CDMA networks

by Arad, Seyed Mohammad

RESOURCE -4LLOC-4TION AND CH-%NYEL ACCESS CONTROL 1s MULTIMEDI-4 WIRELESS CDLVI-A SETWORKS Seyed Mohammad Ali Arad Doctor of Philosophy, 2000 Graduate Department of Electrical and Cornputer Engineering University of Toronto Wireless communication networks have been growing rapidly in recent years. Future wireless networks wili extend the services of existing wireless systems and provide a wide range of multimedia services to mobile users. Towards multimedia traEc transport over the shared radio channel, the choice of an appropriate Medium Access Control (MAC) protocol is of great importance. Future wireless networks will require a MAC protocol which allocates channel resources to multimedia services according to their Quality-of-Service (QoS) requirements. This thesis explores the issue of QoS provisioning for multimedia services in future wireless Code Division Multiple Access (CDMA) networks. Solutions to resource allocation and channel access problems are proposed which attempt to share radio resources among users in a fair ar1d eEcient manner. A fiamework is developed for QoS provisioning in CDMA systems in which the base station controls multiuser interference in each wireless cell. Using the concept of scheduling in Time Division Multiple Access (TDMA) systems, a hybrid CDlMA/TDMA systern is proposed in which access to channel resources in time and power domains is controlled by the base station. The resource allocation problem of the hybrid system is divided into power control and time scheduling problems. The power control problem is formulated and the optimum power level of each packet transmission is determined. The fair queueing concept is used to develop a resource allocation approach for the class of CDMA systems. A packet-based approximation of this approach is then presented as the time scheduling scheme of the hybrid system. The integration of time scheduling and power control schemes and the issue of service share assignment in the hybrid system are also addressed. Using the wideband CDMA technology, a system architecture is presented for the hybrid system. A MAC protocol is then developed for this system which employs a simplified version of our proposed scheduling scheme- Several signaling mechanisms are proposed which allow different mobiles to send scheduling-related control information to the base station. To demonstrate multimedia support capabilities of the hybrid system and examine the performance of proposed signaling mechanisms, simulations are performed with various mixes of multimedia services. iii